We propose to continue studies on the influence of sulfite on developmental processes, utilizing a sulfite oxidase-deficient rat model. Additional data will be gathered during this teratological evaluation to determine the sensitivity of these animals to anemia and thiamine deficiency, two forms of sulfite toxicity previously demonstrated in normal rats at very high sulfite doses. Using this same animal model, we will investigate biochemical signs of altered metabolism such as increased production of S-sulfonate and thiosulfate compounds and decreased oxidation of intravenously injected sulfite. Possible toxic effects of in vivo sulfitolysis of aorta tissue will be investigated by measuring the stress-strain relationships in tissue from sulfite-treated and control animals.